1. Field of the Invention
This invention relates generally to an improved water-armed/air-safed ordnance apparatus, and more particularly to an explosively actuatable pusher piston and valve sleeve arrangement in combination with a ball lock piston type mechanism to assure positive separation of a firing device from a release device in a water environment while assuring added protection against inadvertent out-of-water-operation.
2. Description of the Prior Art
Ball lock piston type mechanisms are well known in the prior art. They have been used in the past, in combination with explosive actuators, to cause remote release or separation of a firing device and/or payload package (explosive firing devices and line charges), from, for example, a non-expendable pod attached to a launching vehicle flying over a water environment.
One such apparatus using, inter alia, a ball lock piston type mechanism, is disclosed in U.S. Pat. No. 2,996,990 to Leaman, entitled "Explosive Actuator", filed Oct. 15, 1953, and assigned to the same assignee as the present invention. In Leaman, an actuatable apparatus provides for release of a ball type locking device when an explosive charge, sealed within the body of the apparatus, is fired in response to an electrical impulse.
According to Leaman, a high pressure gas from an explosive actuator is confined to a sealed chamber intermediate a ball detent plunger (piston) and the aforementioned explosive actuator. The high pressure gas generated in the sealed chamber is predetermined and sufficient to cause release of the plunger (piston) by shearing off a conical flange portion (lip) thereof. While, Leaman, discloses specific mechanisms for explosive actuation and ball detent release of payloads and the like, he does not consider water-armed/air-safed functions and features which today is considered an important operational function of apparatus of this class and kind.
Consequently, in a water environment, proper operational techniques require separation of a payload or firing device from a pod only when the pod is underwater safely away from the launching vehicle. In addition, for safety of personal and property, this separation must not occur when the device is inadvertently actuated in an air environment.
As stated, ball locking mechanisms used in situations as described hereinabove do not provide the required out-of-water safety. Accordingly, there is a need in the prior art, when using ball lock piston type mechanisms in combination with release devices, actuator devices and firing devices to be able to remotely release a firing device in a water environment and not in an air environment while assuring positive separation in the water environment and providing improved out-of-water protection.
A recent design added a water-armed/air safed feature to an apparatus similar to the one disclosed in Leaman. This design contemplated driving a ball lock piston type mechanism via a water column using only the high gas pressure of an explosive actuator (squib) to compress the water column. The pressure generated by this technique is not sufficient to reliably drive the apparatus of the present invention and maintain safe out-of-water protection. However, the technique has been used with hand grenades and like devices with some success. For example, see U.S. Pat. No. 3,765,332 to Baker et al, entitled, "Water-Armed, Air-Safetied [sic] Detonator", filed Mar. 27, 1972, and assigned to the same assignee as the present invention.
Another recent design revised the foregoing design by adding a primary piston for compressing the water column. This design is disclosed in U.S. Pat. No. 3,765,331 to Montesi, also entitled, "Water-Armed Air Safetied [sic] Detonator", filed Apr. 11, 1972, and assigned to the same assignee as the present invention. In Montesi, a water-armed/air-safed fuze device for use with hand grenades, mines, bombs and the like permits initiation of a main charge connected thereto only when the device is under water.
According to Montesi, a chamber having orifices opened to the environment is intermediate an explosively driven piston (primary piston) and a percussion primer. When water fills the chamber it is compressed by the explosively driven piston causing shearing off of the lip of a firing pin. The firing pin is then ejected into the percussion primer thereby initiating the main charge. When air fills the chamber and is compressed, the pressure generated is insufficient to shear off the lip of the firing pin, and, accordingly, the device is safed.
While Montesi discloses a device that operates to capture a column of water and then compress that column to generate a driving pressure for a primary piston, the normal compression of the water causes an appreciable amount thereof to escape through the orifices thereby decreasing the available drive pressure. The available drive pressure is possibly sufficient to reliably operate Montesi's device when used with firing pins in hand grenades and the like. However, it is not large enough to reliably operate the ball lock piston type mechanism contemplated for use with the present invention since it was found that the resultant pressure was not sufficient to shear off the annular lip of the ball lock piston used. Also, it was found that reducing the strength of the annular lip of the ball lock piston resulted in a safety comprise from an inadvertent initiation in an air environment specifically, or from vibration and shock in general.
Thus, there is a need in the prior art to increase the available device pressure when compressing a column of water sufficiently to shear off the annular lip of a ball lock piston type mechanism while maintaining improved protection against out-of-water operation when the apparatus is inadvertently actuated in air or subjected to shock and vibration.
An additional problem with the prior art water-armed/air-safed apparatuses of the class and kind of Montesi and Baker et al, is that when they are inadvertently submerged in water and subsequently retrieved, they become unsafe in air due to the difficulty of entrapped water to escape. Thus, they can cause property damage and injury or death to an unwitting user and other personnel in the area.
Hence, there is a need in the prior art to configure a water-armed/air-safed release apparatus in an improved manner so that it is safe to handle in air even when inadvertently submerged in water and subsequently retrived without actuation.
The representative prior art, as outlined hereinabove, include many advances in release or separation apparatus with water-armed/air-safed features including primary pistons. However, insofar as can be determined, no prior art water-armed/air-safed release apparatus incorporates all of the features and advantages of the present invention.